It is known from British Pat. No. 926,722 to provide a medical support consisting of a flexible bag made of synthetic plastic material, filled with a granular material. The bag is fitted with a valve, so that the bag can be maintained in a condition evacuated of air. In use, the bag in its non-evacuated state is pushed against a patient to be supported and the granular material flows to allow the bag to take up a shape closely conforming to the shape of the patient. The bag is then evacuated of air through the valve, causing the granular material to become compressed by virtue of the resulting pressure differential across the flexible wall of the bag. As a result, the previously flexible support device becomes rigid, with the granular material becoming locked into a rigid support mass in a shape closely conforming to the shape of the body being supported.
British Pat. No. 1,095,311 discloses a similar arrangement, used to package delicate objects.
These prior arrangements provide a support which intimately conforms to the shape of an object being supported. However, in order for the rigid support to be maintained, the bag must be maintained in its evacuated condition. Maintenance of the evacuated condition over long periods of time, e.g., weeks or months, as would be required say for a medical splint, is difficult to achieve, and for the packaging application, if the bag becomes punctured in transit, the intimate support for the packaged article is lost.